Mark Danner's powerful address on the Iraq War, noted by Marty below, prompted me to reflect on an essential difference between how our leaders wage war and how it was done in the medieval days, as described by Martin van Creveld (in The Rise and Decline of the State):

Having defeated their rivals by one method or another, the monarchs soon began to change the way they did business and presented themselves to the world. One of the earliest, and most important, changes took place in the military field. Owing partly to the personal nature of politics, partly to the knightly ethos, medieval rulers had normally commanded their armies in person and often fought hand to hand in the front ranks. Consequently casualties among them were by no means rare: some died; others were taken prisoner and had to be ransomed. For example, both the king of France and his heir were captured at the Battle of Poitiers in 1356. James IV of Scotland was killed at Flodden in 1513; as already noted, the Battle of Pavia in 1525 ended with the capture of King Francis I of France. Not to be outdone, Francis' rival Charles V fought hand to hand in front of the walls of Tunis and had several horses killed under him....

By contrast Charles' prudent son Philip II preferred to direct the far-flung campaigns by bureaucratic methods, relying on field commanders whom he selected from the highest nobility and surrounded with closely worded letters of instruction. By the time of the Thirty Years War his approach had come to be shared by most of the principal monarchs....

During the eighteenth century, the decline of the number of royal field commanders continued....To compensate themselves for the lost joys of battle, some eighteenth-century monarchs, especially Louis XIV, would present themselves at the end of a siege, assume formal command, and put on heroic airs.

That last bit sounds like President Bush's "Mission Accomplished" moment on the aircraft carrier.

There is something to be said for the long lost "knightly ethos." Wars are easier to start and continue when one's own life is not on the line.

It's worth noting that there was in fact one U.S. CinC who, while President, did lead the troops into battle: George Washington.

In August 1794, in response to tax protests in Pennsylvania, George Washington declared martial law, and then marched an army of over 10,000 men (as large as any contingent he ever led during the Revolutionary War) to what is today Monongahela. Opposition, as it turned out, evaporated in the face of this force. But Washington himself did in that case physically lead the troops into the fray,

"Wars are easier to start and continue when one's own life is not on the line."

History has numerous examples of leaders in the pre-nation state days taking the field regularly, and risking themselves to do so (e.g. Gustavus Adolfus, Caesar, Alexander, Charlemagne, as well as the English leaders in the Wars of the Roses). Usually, only the stable imperial states were able to do away with this to any great degree, but always at the risk of a revolt by a successful commander (most of the later Roman Empire).

In the medieval period, armies were often formed of the nobility, their families, and personal retainers, which did increase personal risk, but that seemed to little dissuade the personal involvement in warfare.

On second thought, that last note does not sound quite right, mainly because courageous opponents of the Vietnam war also refused to go (although they did so openly and paid a price). What I should have said is that leaders who lack the courage of their convictions would be more reluctant to start and continue wars...

While it's nice to think about how many fewer wars there might be if the President led them personally, it misses one key component of American government: civilian leadership of the military. We don't put the executive in the field partly out of safety concerns, but also partly because keeping that disconnect between the person who dictates our policy and the person giving orders in the field is important.